What is the best way to ensure proper trailer alignment while coupling?

Answer: B — Back straight and use mirrors to align the tractor with the trailer

Using mirrors to back straight and align the tractor with the trailer is the best method for ensuring proper trailer alignment while coupling. This technique allows the driver to maintain a clear view of both the tractor and the trailer, facilitating precise adjustments as necessary. Mirrors provide a wider perspective than relying solely on instinct, helping to reduce blind spots and potential misalignment. By backing straight, the driver can avoid unnecessary angles that could complicate the coupling process, leading to a more efficient and safe maneuver. While adjusting the trailer's height before backing up can be helpful, it is not sufficient as a standalone method for ensuring proper alignment. Similarly, asking someone to guide while backing can introduce variability and potential hazards, especially if communication is not clear. Therefore, relying on mirrors and maintaining a straight backing approach is a more effective and safer strategy for achieving proper trailer alignment.